In recent years, fiber optic technology has revolutionized medical procedures. Nowhere have the advantages engendered by these advances been greater than in the area of surgical techniques. Due to their flexibility and relatively small size, surgical devices incorporating flexible light pipes (such as fiber optics) may be inserted into bodily cavities through relatively small incisions, whereas prior to the advent of this technology, large incisions, and therefore major surgery was required for such access.
Fiber optic surgical devices, once positioned within the bodily cavity, may be used to view body tissues contained within the cavity, and if properly adapted, to cut and remove undesired bodily tissue from the body cavity. It is often particularly useful for such fiber optic cutting devices to use a coherent beam of electromagnetic radiation (e.g. a laser beam) to thermally damage undesired tissues. When struck by a low-power coherent beam, the undesired tissue may be cauterized and the tissue killed.
It is necessary in such procedures that the coherent beam be directed in a precise manner upon undesired tissue to avoid destruction or removal of healthy, desired tissue. Positioning of the beam is generally achieved by inserting a relatively stiff catheter to serve as mechanical support and guide to the flexible optical fiber. Fiber optic viewing devices are typically carried within the catheter to allow a surgeon to view the target area for initial positioning and for subsequent viewing of the target area during operation. Once the catheter is positioned adjacent the target tissue, the fiber optic cutting device is inserted through the catheter and extended slightly past its distal end in close proximity to the target tissue. The coherent beam of electromagnetic radiation may then be supplied through the cutting device to illuminate and destroy undesired tissue.
When this occurs, the efficiency of the procedure is significantly reduced. One consequence of tissue accumulation on the fiber is increased difficulty in positioning the fiber adjacent the target tissue. The fiber optic viewing device can become blocked by the tissue, thereby impairing the surgeon's view of the probe to the point where continued operation may become impossible.
Tissue which accumulates on the distal end of the optical fiber may act as an insulator between the fiber optic device and the undesired tissue and absorb some of the beam energy directed upon the target tissue. In order to maintain sufficient beam strength to cauterize the undesired tissue as bodily tissue accumulates on the fiber, it is necessary either to increase the intensity of the beam, or to clean the tissue from the fiber. Beam intensity, however, is a critical factor in fiber optic procedures.
To overcome these problems, therefore, it currently is necessary periodically to remove the fiber from the patient, for cleaning. This cumbersome procedure not only adds a significant amount of time to fiber optic surgery, but also prolongs patient discomfort. Accordingly, there is a need in the art for a more efficient means of cleaning the distal end of a fiber optic probe during surgery.
There have been attempts at providing a catheter system having a means for cleaning the distal end of a catheter as it is withdrawn from a patient. For example, Jinotti, U.S. Pat. No. 5,140,983, discloses a Multipurpose Catheter Assembly with a sponge attached to the assembly for cleaning the catheter as it is withdrawn from a patient. The sponge is affixed to the inner wall of the assembly which is located outside of a patient. The catheter slides through an opening in the sponge and into the patient. When the catheter is withdrawn, the sponge cleans its distal end of mucus and other bodily fluids.
Although providing somewhat effective means for removing undesired tissues after a catheter is withdrawn from a patient, Jinotti's sponge is located outside of the body in a separate assembly. Accordingly, Jinotti fails to address the cleaning of a fiber optic device inside the body using a cleaning means affixed to the interior wall of a catheter. In fact, Jinotti fails to recognize the unique problems associated with the build up of bodily tissue on fiber optic devices during medical procedures.